<html>
<head>
<style>

#centro{

width: 60%;
height: 40%;
border: solid black 1px;

}

</style>
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

</head>
<body>
<div id = "centro">
teste
</div>
</body>
</html>